Find index of first item in sorted list whose key >= start_value.
This function performs a binary search to efficiently locate the leftmost index
where the key of the item is greater than or equal to start_value.
- Parameters:
items (List[Any]) – Sorted list of items.
start_value (Any) – The value to compare to.
key (Callable[[Any], Any]) – Function to extract a comparable key from each item.
- Returns:
Index of the first item with key >= start_value, or -1 if no such item exists.
- Return type:
int